Body surface mapping system

ABSTRACT

A body-surface mapping system is disclosed that uses a plurality of electrodes to map at least a portion of a human torso without having to adjust the positions of the electrodes. The body-surface mapping system energizes groupings or regions of electrodes, then compares and adjusts the current driven through each grouping or region of electrodes to produce near-uniform fields. The electrodes of the body-surface mapping system may be interconnected by wires capable of sensing interelectrode distances, such that the system can reconstruct a detailed model of a patient&#39;s torso surface. The body-surface mapping system may also use a catheter in addition to the body surface electrodes to compute both endocardial and epicardial voltage distributions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. application Ser. No. ______, filed29 Dec. 2006, entitled “Cardiac Navigation System Including ElectrodeArray for Use Therewith” (Attorney Docket No. 2384.0630000), which ishereby expressly incorporated by reference as though fully set forthherein.

BACKGROUND OF THE INVENTION

a. Field of the Invention

The instant invention relates to body-surface mapping of at least aportion of a human torso, and more particularly to methods and systemsfor noninvasive electrophysiology study. In particular, the instantinvention relates to a garment or vest comprising a plurality ofelectrodes that are preferably interconnected. The garment or vest mayby used alone or in combination with a catheter or probe to calculateendocardial and epicardial voltages to map and/or treat the human heart.

b. Background Art

Imaging and diagnosing cardiac electrical activity can be problematicbecause the electrical activity is time dependent and spatiallydistributed throughout the myocardium. Electrocardiographic techniquesthat include, for example, electrocardiograms (ECG) andvectorcardiography (VCG) can be limited in their ability to provideinformation and/or data on regional electrocardiac activity. Thesemethods' can also fail to localize bioelectric events in the heart.

Simultaneous recordings of potentials at tens or hundreds of locationson the torso, for example, is known and can provide body surfacepotential maps (BSPMs) over the torso surface. Although the BSPMs canindicate regional cardiac electrical activity in a manner that may bedifferent from conventional ECG techniques, the known BSPM techniques,on their own, may provide a comparatively low resolution, smoothedprojection of cardiac electrical activity that does not facilitatevisual detection or identification of cardiac event locations (e.g.,sites of initiation of cardiac arrhythmias) and details of regionalactivity (e.g., number and location of arrythmogenic foci in the heart).

It is also common to measure the electrical potentials present on theinterior surface of the heart as a part of an electrophysiological studyof a patient's heart. Typically such measurements are used to form atwo-dimensional map of the electrical activity of the heart muscle. Anelectrophysiologist will use the map, for example to locate centers ofectopic electrical activity occurring within the cardiac tissues. Onetraditional mapping technique involves a sequence of electricalmeasurements taken from mobile electrodes inserted into the heartchamber and placed in contact with the surface of the heart. Analternative mapping technique takes essentially simultaneousmeasurements from a floating electrode array to generate atwo-dimensional map of electrical potentials.

The two-dimensional maps of the electrical potentials at the endocardialsurface generated by these traditional processes may be less than ideal.Traditional systems have been limited in resolution by the number ofelectrodes used. The number of electrodes dictated the number of pointsfor which the electrical activity of the endocardial surface could bemapped. Therefore, progress in endocardial mapping has involved eitherthe introduction of progressively more electrodes on the mappingcatheter or improved flexibility for moving a small mapping probe withelectrodes from place to place on the endocardial surface. Directcontact with electrically active tissue is required by most systems inthe prior art in order to obtain well conditioned electrical signals.

With an increasing use of nonpharnacological anti-arrhythmicinterventions (e.g., ablation), comparatively rapid and accuratelocalization of electrocardiac events—both endocardial andbody-surface—can be beneficial.

BRIEF SUMMARY OF THE INVENTION

It is desirable to improve currently known systems for electrophysiologystudy. The present invention relates to such an improved system andmethods of its use. More specifically, the present inventioncontemplates a system for body-surface mapping of electrical potentialsof at least a portion of a human body, using a plurality of electrodes.The mapping system may comprise a flexible garment (e.g., a vest, largepatch, or other structure) adapted to fit at least a portion of thehuman body, the flexible garment supporting a plurality of electrodes. Aportion of the plurality of electrodes may be arranged in a plurality ofregions. The mapping system may further have a localization system todetermine relative distances between at least two regions of electrodesand an electronic device with a software program adapted to measure, andin some embodiments also to control, the drive currents for at least tworegions of electrodes and to measure the linearities, and in someembodiments also the homogeneities, of the electrical fields created bythose at least two regions. In such a mapping system of the presentinvention, the software program may compare the various regions ofelectrodes and identify at least one region that creates an electricalfield that is more linear than, and in some embodiments also morehomogeneous than, an electrical field generated by another region. Amemory coupled to the electronic device could store informationregarding the identified region or regions of most linear and/or mosthomogeneous electrodes, with the stored information comprising the drivecurrents for that region, and, in some embodiments, an identification ofthe electrodes within that region. Such a system could permit creationof near-uniform fields and allow for improved body-surface mapping of aportion of the human torso.

A plurality or all of the electrodes in the garment of the inventivemapping system may further be interconnected. These electrodes may beinterconnected by piezoelectric wires such that relative distancesbetween a plurality of the electrodes may be determined usinginformation about stress forces that are applied to the plurality ofpiezoelectric wires. Further, the localization system of the presentinvention may comprise a device that can determine position informationfor some or each of the plurality of electrodes. The positioninformation could comprise interelectrode spacings, such that threedimensional positions of some or each of the plurality of electrodes maybe calculated.

The garment of the novel mapping system may further have a plurality ofelectrodes arranged in a plurality of rows, where the rows may be placedabout the circumference of the human body. The garment may further havea plurality of spacers designed to locate at least one of the pluralityof rows at fixed distances from adjacent rows, wherein the lengths ofthe plurality of spacers would be known to the mapping system. Some oreach of the plurality of rows may further be adjustable such that acircumference measurement for each row of electrodes may be determinedby the system. Such a system of the present invention may further havean adjustable member coupled to the system such that the circumferencemeasurement could be measured automatically by the mapping system. Suchan embodiment of the body-surface mapping system of the presentinvention could provide even more accurate measurements of body-surfacepotential for each patient.

The mapping system of the present invention may further comprise one ormore catheters or probes adapted to move throughout the heart or a heartchamber. The electronic device of the system may then be capable ofcollecting data from both the plurality of electrodes and the cathetersor probes to collect, e.g., both body-surface potentials andintracardiac voltages.

A different embodiment of the body-surface mapping system of the presentinvention may have a flexible vest adapted to fit at least a portion ofthe human torso, the flexible vest having a plurality of electrodes. Themapping system may also have a localization system to determine relativedistances between a plurality of pairs of the plurality of electrodesand an electronic device capable of electronically connecting to theflexible vest. The electronic device may have a processor to determineoptimal drive currents for the plurality of electrodes to create ahomogeneous and linear electrical field in which a position of a sensorlocated within an interior of the human torso can be determined withrespect to at least two orthogonal axes. This mapping system wouldfurther have a software program, which may provide position informationof the sensor within the human torso.

The flexible vest of the novel system may further have at least 128electrodes and at least two of the electrodes may be interconnected bypiezoelectric or mechanical wires. This mapping system may further havea balloon catheter, which may be a multi-electrode balloon catheter, forinsertion into the human body. The software program of the system maythen be adapted to electronically connect to the balloon catheter andfurther adapted to compute both epicardial and endocardial voltagedistributions from measurements made by the balloon catheter and/or aplurality of the electrodes. The software program may further be adaptedto measure voltages relative to at least the balloon catheter.

The flexible vest may further have a plurality of electrodes arranged ina plurality of rows, wherein the plurality of rows may be placed about acircumference of the human body. This vest could then further have aplurality of spacers designed to locate at least one of the plurality ofrows at fixed distances from adjacent rows, wherein the lengths of thespacers would be known to the mapping system. The plurality of rows mayfurther be adjustable such that a circumference measurement for each rowof electrodes of the plurality of rows may be determined by the system.The plurality of rows of electrodes may further include an adjustablemember coupled to the system such that the circumference measurementcould be measured automatically by the system.

In another aspect, the present invention may be a device capable ofdetermining the torso geometry of a human. Such a device may have aplurality of electrodes arranged in a plurality of rows, wherein theplurality of rows may be placed about a circumference of a portion ofthe human. The plurality of electrodes may be supported or encompassedby a semirigid, flexible material. The device may further have anelectronic device capable of electronically connecting to the pluralityof electrodes. In such an embodiment, at least one of the plurality ofrows of electrodes may be arranged to form a circumferential row ofelectrodes having a closure member at at least one end. The closuremember could have an electrical contact such that when the closuremember is used to secure the device to a human, the closure member iscapable of registering information regarding a closing position. Theelectronic device could then comprise software adapted to compute atorso model of the human based on the closing position of the closuremember. The closure member may be a snap fastened along a side of thedevice that is opposite a side of the device that would be placed near aheart of a human patient upon whom the device is placed. Each electrodeof the inventive device may be further connected to at least one otherelectrode by mechanical wires such that the electrodes areinterconnected.

The present invention further relates to a method for measuring ordetermining epicardial and endocardial voltages and/or potentials in ahuman. According to such a method, a device having a plurality ofelectrodes may be applied to a portion of the torso of a human tomeasure body-surface potentials. A catheter such as a balloon catheteror mapping catheter may also be directed into the cardiac region of thehuman patient to measure an intracardiac voltage. Software may then beused to collect the body-surface potentials and intracardiac voltagesand to concurrently reconstruct epicardial and endocardial voltagedistributions. The electrodes in the device used in such a method may beinterconnected by piezoelectric wires such that relative distancesbetween a plurality of the electrodes may be determined usinginformation about stress forces that are applied to the plurality ofpiezoelectric wires. The plurality of electrodes of the device mayfurther be arranged in a plurality of regions of electrodes such that atleast two of the regions of electrodes may each be energized with adifferent current such that measurement of the epicardial voltagedistribution can be made in a plurality of regions without adjusting theposition of the plurality of electrodes. In such a method, the softwaremay be adapted to control and measure the drive currents for at leasttwo regions of electrodes and to measure the homogeneity and linearityof an electrical field created by the at least two regions, such thatthe software may compare the relative linearities for a plurality ofregions of electrodes and identify and control a region of electrodesthat creates an electrical field that is more linear than an electricfield generated by at least one other region.

The foregoing and other aspects, features, details, utilities, andadvantages of the present invention will be apparent from reading thefollowing description and claims, and from reviewing the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing one embodiment of a body-surfacemapping system of the present invention, having a plurality ofinterconnected electrodes connected to a computer system comprising alocalization system.

FIG. 2 is a block diagram showing another embodiment of a body-surfacemapping system of the present invention, having a plurality ofelectrodes supported in a semirigid, flexible garment with a closuremember along one side.

FIG. 3 is a block diagram showing another embodiment of a body-surfacemapping system of the present invention, having a vest with a pluralityof electrodes and a catheter both connected to a computer system forcomputing both endocardial and epicardial voltages.

DETAILED DESCRIPTION OF THE INVENTION

The present invention generally relates to a system or device useful forbody-surface mapping, myocardial activation pattern mapping, ordetermining the torso geometry of a human. In various preferredembodiments, the system or device has a plurality of electrodes dividedinto regions or groupings of electrodes such that different regions orgroupings may be energized. The regions or groupings of electrodes neednot be physically segregated. Indeed, in several preferred embodiments,the regions or groupings of electrodes are variable, such that, forexample, in a device with 128 electrodes, there may be as many assixty-four regions or groups of electrodes, or as few as two regions orgroups of electrodes, and the regions or groups may comprise as few astwo or as many as 126 neighboring or adjacent electrodes.

In some preferred embodiments, a software program measures the drivecurrents for at least two regions of electrodes and measures thelinearity of an electrical field created by those regions (that is, itmeasures the linearity of each electric field created by each of the atleast two regions of electrodes). The software program may also beadapted to control the drive currents for at least two regions ofelectrodes. In addition to measuring the linearity of the electricalfields, the software program may also measure the homogeneity of theelectrical fields. The software program can then compare the variousregions of electrodes and identify at least one region that creates anelectrical field that is more linear, and, in some embodiments, morehomogeneous, than an electrical field generated by another region. Thesoftware program could also be adapted to mate different electrodes tofind an electrode pairing that provides a more linear or morehomogeneous field than that generated by another electrode pairing.These preferred embodiments allow for the creation of precise andnear-uniform fields, thereby allowing for more accurate and improvedbody-surface mapping of a portion of the human torso, particularly thecardiac area. Specifically, near-uniform fields may be created based onusing a patient-specific torso model or morphing a representativesolution onto a patient's surface geometry. In one preferred embodiment,the system or device employs a roving catheter or probe to sendelectrical feedback as the catheter or probe is moved to variouspositions in the heart while different source current distributions areapplied to the body-surface electrodes.

FIG. 1 demonstrates a body-surface mapping system according to some ofthe preferred embodiments of the present invention. As shown, aplurality of electrodes 100 are located on a human torso 10. Theelectrodes may be supported by a garment 250, such as a vest 300 (shownin FIG. 3), a large patch, an elastic belt, or the like. Thebody-surface mapping system may have any number of electrodes. In apreferred embodiment, the body-surface mapping system has at least 64electrodes. In a further preferred embodiment, the body-surface mappingsystem has at least 128 electrodes. In yet another preferred embodiment,the body-surface mapping system has at least 256 electrodes.

The electrodes 100 are connected to navigation field current drivers 150that are part of a localization system 190 that also comprises alocation and navigation system 130 and a field homogeneity adjustment135. The localization system 190 is coupled to an electronic device witha software program 170 or multiple software programs. The localizationsystem 190 and software program 170 may all be housed within the samecomputer system 110, as shown, and may run using a related family ofalgorithms, or may be resident on different computer systems. Theelectrodes 100 may be energized by the current drivers 150 in differentgroupings or regions of electrodes. The location and navigation system130 then measures the relative distances between at least two regions orgroupings of electrodes while the software program 170 measures thedrive currents for the energized regions of electrodes. The homogeneityand linearity of an electrical field created by the various regions orgroupings of electrodes is thereby measured. The software program 170then compares the relative linearities, and in some embodiments therelative homogeneities, of the electrical fields created by the variousregions or groupings of electrodes and identifies at least one region orgrouping that creates an electrical field that is more linear and/orhomogeneous than an electrical field generated by another region. Thesoftware program 170 and the location and navigation system 130 alsosend information to the field homogeneity adjustment 135 that cancommunicate with the current drivers 150 to energize a differentgrouping or region of electrodes. The software program could also beadapted to mate different electrodes to find an electrode pairing thatprovides a more linear or more homogeneous field than that generated byanother electrode pairing. As a result, a more homogeneous electricfield is established for navigation and mapping with improved accuracy.The computer system 110 of FIG. 1 further has a memory 180 to storeinformation regarding the identified region or regions of electrodes ofmost linear and/or homogeneous fields, including the drive currents forthat region or regions. The memory 180 may be part of the computersystem 110 or may be coupled to the computer system 110. In someembodiments, the resulting data can be viewed on a display 140, whichmay also be coupled to or part of the computer system 110.

As further shown in FIG. 1, in some preferred embodiments, at least aportion of the plurality of electrodes 100 is interconnected. Theelectrodes 100 may be interconnected by piezoelectric wires 190 ormechanical wires able to determine the distance between many or at leasta pair of neighboring electrodes 100. The piezoelectric wires 190 usestress forces applied to the wires to determine relative distancesbetween the interconnected electrodes. This electrode spacinginformation can be used by the location and navigation system 130 and/orby the software program 170 to further optimize field uniformity.

In another embodiment of the present invention, as shown in FIG. 2, aplurality of electrodes 100 is supported or encompassed by a semirigid,flexible material 350. In this embodiment, the electrodes 100 may bearranged in a plurality of rows. The semirigid material stretches onlyin circumference along each row of electrodes. The semirigid materialhas a closure member 360 at one end. The closure member may have severalstraps or snaps that have an electrical contact such that when theclosure member is used to secure the device to a human, the snaps orstraps register the position in which they are closed. This positioninformation is then communicated to the location and navigation system130 and/or a software program 180 (which may be the same or differentfrom the software program 170 of FIG. 1). The software program 180 thencomputes a patient-specific torso model based on the patient's torsocircumference at each row of electrodes. The semirigid, flexiblematerial may be in the shape of a vest or other suitable garment. Inorder to accommodate a wide variety of human torso sizes, such a vest orother suitable garment may come in a variety of sizes.

The geometry and conductivity information collected by the systems ofthe present invention, as shown in FIGS. 1 and 2, may be used toreconstruct epicardial potentials, by using the plurality of electrodesas passive sensors of the fields created by myocardial activation. Forexample, by measuring torso potentials at each electrode position, aboundary element algorithm (similar to, e.g., the Ensite™ algorithm)could estimate potentials everywhere on the epicardium. The potentialscould be displayed in real time or saved in memory and viewed in areview mode to aid in clinical diagnosis.

In some embodiments of the present invention, as shown in FIG. 3, thebody-mapping surface system further comprises a catheter 200. Thecatheter may be a mapping catheter, a sensor probe, or a multi-electrodecatheter such as the Ensite™ balloon catheter. The mapping catheter 200is also linked to a software program 160. As shown, the software program160 is part of computer system 110 but is a different program thansoftware program 170. In some preferred embodiments, the softwareprograms 160 and 170 are part of the same software program. In otherpreferred embodiments, the software programs are resident on separatecomputer systems. The localization and mapping systems described in thefollowing patents, which are all incorporated herein by reference intheir entireties, can be used with the present invention: U.S. Pat. Nos.6,990,370, 6,978,168, 6,947,785, 6,939,309, 6,728,562, 6,640,119. Theuse of other localization and mapping systems is also contemplated.Using the catheter 200 in conjunction with the plurality of body-surfacemapping electrodes 100, the system of the present invention shown inFIG. 3 is able to measure both body-surface potentials and intracardiacvoltages to compute both endocardial and epicardial voltages.

Some preferred embodiments of the present invention, for example theembodiment depicted in FIG. 3, may be used in a method to computeendocardial and epicardial voltages from a human patient. A vest 300having a plurality of electrodes 100 may be applied to a portion of thetorso of a human 10 to measure body-surface potentials. A catheter 200such as a balloon catheter or mapping catheter may also be directed intothe cardiac region of the human patient to measure an intracardiacvoltage. Software programs 160 and 170 may then be used to collect thebody-surface potentials and intracardiac voltages and to concurrentlyreconstruct epicardial and endocardial voltage distributions. Theelectrodes 100 in the device used in such a method may be interconnectedby piezoelectric wires 190 such that relative distances between aplurality of the electrodes may be determined using information aboutstress forces that are applied to the plurality of piezoelectric wires190. The plurality of electrodes 100 of the vest may further be arrangedin a plurality of regions of electrodes such that at least two of theregions of electrodes may each be energized with a different currentsuch that measurement of the epicardial voltage distribution can be madewithout adjusting the position of the plurality of electrodes 100. Insuch a method, the software may be adapted to control and measure thedrive currents for at least two regions of electrodes and to measure thehomogeneity and linearity of an electrical field created by the at leasttwo regions, such that the software may identify a region of electrodesthat creates an electrical field that is more homogeneous and linearthan an electric field generated by at least one other region.

Although only a few embodiments of this invention have been describedabove with a certain degree of particularity, those skilled in the artcould make numerous alterations to the disclosed embodiments withoutdeparting from the spirit or scope of this invention. In addition, thebody-surface mapping system of the present invention may be utilized todrive enough current through regions or groupings of electrodes toestimate the conductivity of a variety of tissues within the humantorso, such as lung, blood, bone, and muscle, and may also be capable ofdetermining the relative positions, conductivities, and sizes of suchtissue.

All directional references (e.g., upper, lower, upward, downward, left,right) are only used for identification purposes to aid the reader'sunderstanding of the present invention, and do not create limitations,particularly as to the position, orientation, or use of the invention.Joinder references (e.g., attached, coupled, connected, and the like)are to be construed broadly and may include intermediate members betweena connection of elements and relative movement between elements. Assuch, joinder references do not necessarily infer that two elements aredirectly connected and in fixed relation to each other.

It is intended that all matter contained in the above description orshown in the accompanying drawings shall be interpreted as illustrativeonly and not limiting. Changes in detail or structure may be madewithout departing from the spirit of the invention as defined in theappended claims.

1. A system for body-surface mapping of electrical potentials of atleast a portion of a human body, the system comprising: a) a flexiblegarment adapted to fit at least a portion of the human body, saidflexible garment comprising a plurality of interconnected electrodeswherein at least a portion of the plurality of electrodes are arrangedin a plurality of regions of electrodes; b) an electronic device havinga software program adapted to measure drive currents for at least tworegions of electrodes and to measure linearities of at least twoelectrical fields created by the at least two regions of electrodes,such that the program may compare the at least two regions of electrodesand identify at least one region that creates an electrical field thatis more linear than an electrical field generated by at least one otherregion; and c) a memory coupled to said electronic device for storinginformation regarding at least the identified at least one region ofelectrodes, said stored information comprising the drive currents forthe at least one region.
 2. The system of claim 1 wherein said softwareprogram is further adapted to measure homogeneities of the at least twoelectrical fields created by the at least two regions of electrodes,such that the program may identify at least one region that creates anelectrical field that is more homogeneous than an electric fieldgenerated by at least one other region.
 3. The system of claim 1 whereinsaid software program is further adapted to control drive currents forthe at least two regions of electrodes.
 4. The system of claim 1 whereinthe plurality of interconnected electrodes are interconnected bypiezoelectric wires such that relative distances between a plurality ofthe electrodes may be determined using information about stress forcesthat are applied to the plurality of piezoelectric wires.
 5. The systemof claim 1 further comprising a localization system to determinerelative distances between at least two regions of electrodes.
 6. Thesystem of claim 5 wherein the localization system comprises a devicethat can determine position information for each of the plurality ofelectrodes, said position information comprising interelectrodespacings, such that three dimensional positions of each of the pluralityof electrodes may be calculated.
 7. The system of claim 1 wherein thegarment comprises a plurality of electrodes arranged in a plurality ofrows, wherein the plurality of rows may be placed about a circumferenceof the human body; and a plurality of spacers designed to locate atleast one of said plurality of rows at fixed distances from adjacentrows; wherein the lengths of said plurality of spacers is known to thesystem.
 8. The system of claim 7 wherein each of said plurality of rowsis adjustable such that a circumference measurement for each row ofelectrodes of the plurality of rows may be determined by the system. 9.The system of claim 8 wherein each of said plurality of rows includes anadjustable member coupled to the system such that the circumferencemeasurement is measured automatically by the system.
 10. The system ofclaim 1 further comprising a catheter adapted to move throughout a heartchamber, wherein the electronic device is capable of collecting datafrom both the plurality of electrodes and the catheter.
 11. A system forbody-surface mapping of electrical potentials of at least a portion of ahuman torso, the system comprising: a) a flexible vest adapted to fit atleast a portion of the human torso, said flexible vest comprising aplurality of electrodes; b) a localization system to determine relativedistances between a plurality of pairs of said plurality of electrodes;and c) an electronic device capable of electronically connecting to saidflexible vest, said electronic device comprising a processor to drivecurrents for said plurality of electrodes to create an electrical fieldin which a position of a sensor located within an interior of the humantorso can be determined with respect to at least two orthogonal axes.12. The system of claim 11 wherein at least two of the plurality ofelectrodes are interconnected by piezoelectric wires or mechanicalwires.
 13. The system of claim 12 wherein said flexible vest comprisesat least 128 electrodes.
 14. The system of claim 13 further comprising aballoon catheter and a software program, wherein the software program isadapted to electronically connect to said balloon catheter and whereinthe software program is adapted to compute both epicardial andendocardial voltage distributions from measurements made by the ballooncatheter, a plurality of said plurality of electrodes, or a combinationthereof, and is further adapted to measuring voltages relative to atleast said balloon catheter.
 15. The system of claim 14 wherein the vestcomprises: a plurality of electrodes arranged in a plurality of rows,wherein the plurality of rows may be placed about a circumference of thehuman body; and a plurality of spacers designed to locate at least oneof said plurality of rows at fixed distances from adjacent rows; whereinthe lengths of said plurality of spacers is known to the system.
 16. Thesystem of claim 15 wherein each of said plurality of rows is adjustablesuch that a circumference measurement for each row of electrodes of theplurality of rows may be determined by the system.
 17. The system ofclaim 16 wherein each of said plurality of rows includes an adjustablemember coupled to the system such that the circumference measurement ismeasured automatically by the system.
 18. A method for measuringepicardial and endocardial voltages in a human, said method comprisingthe steps of: a) applying a device to a portion of the torso of thehuman to measure body-surface potentials, the device comprising aplurality of electrodes; b) directing a balloon catheter into thecardiac region of the human patient to measure an intracardiac voltage;and c) using software to collect the body-surface potentials andintracardiac voltages and to concurrently reconstruct epicardial andendocardial voltage distributions.
 19. The method of claim 18 whereinthe plurality of electrodes are interconnected by piezoelectric wiressuch that relative distances between a plurality of the electrodes maybe determined using information about stress forces that are applied tothe plurality of piezoelectric wires.
 20. The method of claim 18 whereinat least a portion of the plurality of electrodes are arranged in aplurality of regions of electrodes, the method further comprising thestep of energizing at least two of said regions of electrodes each witha different current such that measurement of the epicardial voltagedistribution can be made in a plurality of regions of electrodes withoutadjusting the position of the plurality of electrodes.
 21. The method ofclaim 20 wherein the software is adapted to measure the drive currentsfor at least two regions of the plurality of regions of electrodes andto measure the linearity of an electrical field created by said at leasttwo regions, such that the software may compare the relative linearitiesfor a plurality of regions of electrodes and identify a region ofelectrodes that creates an electrical field that is more linear than anelectric field generated by at least one other region of electrodes. 22.A device capable of determining torso geometry of a human, the devicecomprising: a) a plurality of electrodes arranged in a plurality ofrows, wherein the plurality of rows may be placed about a circumferenceof a portion of the human; b) a semirigid, flexible materialencompassing the plurality of electrodes; and c) an electronic devicecapable of electronically connecting to said plurality of electrodes;wherein at least one of the plurality of rows of electrodes iscircumferentially arranged to form a circumferential row of electrodesand wherein the circumferential row has a closure member at an end ofthereof; said closure having an electrical contact such that when saidclosure member is used to secure the device to the human, the closuremember is capable of registering information regarding a closingposition and wherein the electronic device comprises software adapted tocomputing a torso model of the human based on the closing position ofsaid closure member.
 23. The device of claim 22 wherein the closuremember is a snap fastened along the a side of the device that isopposite a side of the device that would be placed near a heart of ahuman patient upon whom the device is placed.
 24. The device of claim 23wherein the device is a vest.
 25. The device of claim 22 wherein eachelectrode of the plurality of electrodes is connected to at least oneother electrode of the plurality of electrodes by mechanical wires tomake interconnected electrodes.
 26. The device of claim 22 having aplurality of groupings of electrodes to form regions of electrodeswherein each said region of electrodes is capable of being energized bya different current.
 27. A system for body-surface mapping of electricalpotentials of at least a portion of a human torso, the systemcomprising: a) a flexible garment adapted to fit at least a portion ofthe human torso, said flexible garment comprising a plurality ofelectrodes arranged to form a plurality of regions of electrodes; and b)an electronic device capable of electronically connecting to saidflexible garment, said electronic device comprising a processor todetermine optimal drive currents for said plurality of electrodes and totake resulting measurements, said electronic device further capable ofenergizing said plurality of regions of electrodes each with a differentcurrent such that measurements can be made without adjusting theposition of the plurality of electrodes.